Alternative Mating Strategies in Male Morphotypes of the Prawn Macrobrachiumidellaidella (Hilgendorf, 1898)

Abstract

An alternative reproductive behaviour can be defined as any discontinuous variation in an aspect of reproductive behaviour among one sex within a single population. Alternative reproductive behaviours occur in a wide variety of taxa and, when referring to particular aspects of the mating behaviour are commonly termed alternative mating tactics. A close examination of M. idellaidella males reveals that three distinct morphotypes based upon size ranking, the ratio of claw length to body length (relative claw length) which included small male (SM), medium size male (MS) and bigger size male (BS). To know the alternative mating strategies 7 experiments were conducted. The following stocking combinations were tried in the present study: (1) 3 BS males (110-120mm) Vs female (55-90mm); (2) 3 MS males (70-80 mm) Vs female (55-90mm); (3) 6 SM males (45-55 mm) Vs female (55-90mm); (4) 1 blocked BS male and 2 MS males Vs female (55-90mm); (5) 1 BS male and 2 MS males Vsfemale (55-90mm); (6) 1 blocked BS male and 5 SM males Vs female (55-90mm); (7) 1 BS male and 5 SM males Vs female (55-90mm) respectively.